This invention relates to gear selector mechanisms having a gearbox indicator switch.
While the invention is primarily described in relation to automatic transmission controls for motor vehicles, it will be appreciated that the principal of the invention may be applied to manual and semi-automatic gear shift systems as well, and also to transmission controls for static installations or water borne or possibly airborne craft.
Most new motor vehicles having automatic transmission are required to have a system to signal which gear position has been selected. In its simplest form this system may only be required to turn on reversing lights. For some automatic and semi-automatic gear system a switch is required for every possible position of the gear selection mechanism. These switches are then used either to generate an indication of the position selected by the driver via simple lamps and/or to provide start inhibit or other interlock functions at particular positions of the gear system.
The general environment of the gear box and transmission is particularly harsh. It is generally beneath the vehicle where oil, water and dirt can accumulate. For standard mechanical switch mechanisms, this poses a problem of adequate sealing against the ingress of foreign matter which over a period of time would impair the function of the switch.